Cut-off valve



(No Model.) 3

B. F. OLMSTED.

GUT-OFF ALVE. V NQ. 284,472. Patented Sept. 4,1883.

WITNESSES; I INVENTOR Q BY ATTORNEY ject is to cut off steam atdifferent travels of the main piston in the cylinder, according to UNITESTATES PATENT 'QFFICE.

BENJAMIN F. OLMSTED, on GRAND RAPIDS, MICHIGAN. I

CUT-OFF VALVE.

SPEGIFTCATION forming part of Letterslatent No, 284,472, dated September4, 1883. 7

Application filed June 15,1883. (No model.)

an d'useful Automatic Out-Off Valve for Steam- Engines, of which thefollowingis a specification.

My invention relates to improvements in cut-off valves forsteam-engines; and theobthe different labors on the engine on eachhalfstroke, respectively. I attain this object by invention (with suchother parts of an engine 1 pressure from the governor.

as are attached to the part by me invented) on line 3 3 of Fig. 2. Fig.2 is also a vertical sectional view ofthe same on line as x of Fig. 1.

Similar letters refer to similar parts throughout the several views. 1,

In the drawings, L is the oompressionrod, operated by the governor,which governor is not shown in the drawings, as it is no part of myinvention. I

R is a spring designed to counteract the U is apiston, so placed that itis depressed by the action of the rod L, and depresses the parallelplanes T T, which planes are placed above the roller A A and in contactwith it, as shown in Fig. 2, and the roller A A, with the blades B, journaled thereto, is also depressed, through the piston U and planes TT, by the action of the rod L. The journals are shown by a a a,there-being two or more of these journals.

H is a cut-off valve, so constructed that it receives the sliding bladeB and swings on journals or pivots, and springs c c c are placed inopenings in the valve H, beneath the edge of the blade, so as to pressoutwardly on the presses outwardly on the blade the tendency of thespring is to continuallypress the roller toward the upper part of thesmaller arc M at all times.

n 01. n are vents in valve H to allow the steam to enter and surroundthe blade and hold it in equilibrium.

D is an ordinary D-valve. S and S are steam-ports which receive thesteam from the steam'passages F F and convey it to the cylinder, therebycreating a ourrent of steam alternately through the passages F and F,which steam-current acts alternately first on one side of valve H andthen upon the other. J J are steamvents for the purpose of equalizingthe steam-pressure under the valve H, al lowing the spring to bring thevalve to its nor= mal position when the pressure is equalized.

E is an exhaust for main D-valve. Q is a grip-collar on the, mainvalve-stem P. V, G is the governor steam-chest, restingon the top D ofthe main steam-chest. u u u u are vent-holes extending through piston Uand the base of the governor steam-chest, in order to equalize thesteam-pressure in the governor steam-chest G, as also over and aroundthe governor piston. The counter spring R is regulated by the nut Z, sothat its counteracting stress on rod L maybe increasedor decreased atpleasure.

K K are journals 011 which the valve H turns or swings. The socket M mayor may not be the arc of a circle, and the same is true of arcs V V; butthe arcs are so placed that as the roller passes from the arc M to are Vit passes over an angle or obstacle.

The operation of my invention is as follows:

When the engine is set in motion, as the speed increases, the governorrod L depresses the piston U, planes T T, and roller A until the steam,entering the cylinder through port S,

passage F; and," as the main D-valve reverses its motion, the steam,prior to the opening of port S, passes by means of vent J into passageF, when the spring instantly brings H to its normal position, (shown inFig. 1,) and when port S is opened a reverse current is created andvalve H is carried to the reverse 7. seat on Ffl and the operation isthus continuedand the steam is alternately cut off from passages F andF. If the engine is running rapidly, the depression of the planes T T issuch that roller A cannot pass into socket M but a short distance, andthe valve passes to its seat much more quickly and readily than it willdo with a slower motion, as the angle or obstacle between arc M and areV but slightly retards the roller, and a strong current will force thevalve to its seat much more quickly than a weak or slow current, so thatthe cut off may be at any part of the stroke, and the engine isperfectly regulated and the steam most economically used.

I am aware that automatic cut-off valves are not new, and that there aremany in use, and I do not broadly claim to have invented the same; but Iam not aware that an oscillating valve adjusted by means of slidingblades and. springs, so as to regulate the resistance .by LettersPatent, is

1. In an automatic out 01f valve, the oscillating valve H, incombination with the sliding blade B, spring 0 c a, roller A, and arcs Mand V, all constructed substantially as described.

2. The combination of the spring B, piston U, rod L, planes T T, rollerA, arcs M and V, blade B, and valve H, all constructed and operatedsubstantially as described.

3. In an automatic. cut-off valve, the oscillating valve H, incombination with the steampassages F and F and vents J J, as described.

4.. In an automatic cut-off valve,'the oscillating valve H, incombination with the blade B, spring 0 c c, and vents a a a, for thepurpose described.

5. The following parts in combination, viz: rod L, spring R, piston U,provided with vents u u u u, planes T T, roller A, arcs M V V, blade 45B, valve H, provided with vent n and journals K K, steam-passages F andF, main D- valve D, and vents J J, all constructed as described.

BENJAMIN F. QLMSTED.

Witnesses:

FRED W. SrEvENs, EDWARD TAGGART.

